The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/vm_machdep.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 1982, 1986 The Regents of the University of California.
    3  * Copyright (c) 1989, 1990 William Jolitz
    4  * Copyright (c) 1994 John Dyson
    5  * All rights reserved.
    6  *
    7  * This code is derived from software contributed to Berkeley by
    8  * the Systems Programming Group of the University of Utah Computer
    9  * Science Department, and William Jolitz.
   10  *
   11  * Redistribution and use in source and binary forms, with or without
   12  * modification, are permitted provided that the following conditions
   13  * are met:
   14  * 1. Redistributions of source code must retain the above copyright
   15  *    notice, this list of conditions and the following disclaimer.
   16  * 2. Redistributions in binary form must reproduce the above copyright
   17  *    notice, this list of conditions and the following disclaimer in the
   18  *    documentation and/or other materials provided with the distribution.
   19  * 3. All advertising materials mentioning features or use of this software
   20  *    must display the following acknowledgement:
   21  *      This product includes software developed by the University of
   22  *      California, Berkeley and its contributors.
   23  * 4. Neither the name of the University nor the names of its contributors
   24  *    may be used to endorse or promote products derived from this software
   25  *    without specific prior written permission.
   26  *
   27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   37  * SUCH DAMAGE.
   38  *
   39  *      from: @(#)vm_machdep.c  7.3 (Berkeley) 5/13/91
   40  *      Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
   41  */
   42 
   43 #include <sys/cdefs.h>
   44 __FBSDID("$FreeBSD: stable/9/sys/i386/i386/vm_machdep.c 264148 2014-04-05 14:24:45Z kib $");
   45 
   46 #include "opt_isa.h"
   47 #include "opt_npx.h"
   48 #include "opt_reset.h"
   49 #include "opt_cpu.h"
   50 #include "opt_xbox.h"
   51 
   52 #include <sys/param.h>
   53 #include <sys/systm.h>
   54 #include <sys/bio.h>
   55 #include <sys/buf.h>
   56 #include <sys/kernel.h>
   57 #include <sys/ktr.h>
   58 #include <sys/lock.h>
   59 #include <sys/malloc.h>
   60 #include <sys/mbuf.h>
   61 #include <sys/mutex.h>
   62 #include <sys/pioctl.h>
   63 #include <sys/proc.h>
   64 #include <sys/sysent.h>
   65 #include <sys/sf_buf.h>
   66 #include <sys/smp.h>
   67 #include <sys/sched.h>
   68 #include <sys/sysctl.h>
   69 #include <sys/unistd.h>
   70 #include <sys/vnode.h>
   71 #include <sys/vmmeter.h>
   72 
   73 #include <machine/cpu.h>
   74 #include <machine/cputypes.h>
   75 #include <machine/md_var.h>
   76 #include <machine/pcb.h>
   77 #include <machine/pcb_ext.h>
   78 #include <machine/smp.h>
   79 #include <machine/vm86.h>
   80 
   81 #ifdef CPU_ELAN
   82 #include <machine/elan_mmcr.h>
   83 #endif
   84 
   85 #include <vm/vm.h>
   86 #include <vm/vm_extern.h>
   87 #include <vm/vm_kern.h>
   88 #include <vm/vm_page.h>
   89 #include <vm/vm_map.h>
   90 #include <vm/vm_param.h>
   91 
   92 #ifdef XEN
   93 #include <xen/hypervisor.h>
   94 #endif
   95 #ifdef PC98
   96 #include <pc98/cbus/cbus.h>
   97 #else
   98 #include <x86/isa/isa.h>
   99 #endif
  100 
  101 #ifdef XBOX
  102 #include <machine/xbox.h>
  103 #endif
  104 
  105 #ifndef NSFBUFS
  106 #define NSFBUFS         (512 + maxusers * 16)
  107 #endif
  108 
  109 CTASSERT((struct thread **)OFFSETOF_CURTHREAD ==
  110     &((struct pcpu *)NULL)->pc_curthread);
  111 CTASSERT((struct pcb **)OFFSETOF_CURPCB == &((struct pcpu *)NULL)->pc_curpcb);
  112 
  113 static void     cpu_reset_real(void);
  114 #ifdef SMP
  115 static void     cpu_reset_proxy(void);
  116 static u_int    cpu_reset_proxyid;
  117 static volatile u_int   cpu_reset_proxy_active;
  118 #endif
  119 static void     sf_buf_init(void *arg);
  120 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL);
  121 
  122 LIST_HEAD(sf_head, sf_buf);
  123 
  124 /*
  125  * A hash table of active sendfile(2) buffers
  126  */
  127 static struct sf_head *sf_buf_active;
  128 static u_long sf_buf_hashmask;
  129 
  130 #define SF_BUF_HASH(m)  (((m) - vm_page_array) & sf_buf_hashmask)
  131 
  132 static TAILQ_HEAD(, sf_buf) sf_buf_freelist;
  133 static u_int    sf_buf_alloc_want;
  134 
  135 /*
  136  * A lock used to synchronize access to the hash table and free list
  137  */
  138 static struct mtx sf_buf_lock;
  139 
  140 extern int      _ucodesel, _udatasel;
  141 
  142 /*
  143  * Finish a fork operation, with process p2 nearly set up.
  144  * Copy and update the pcb, set up the stack so that the child
  145  * ready to run and return to user mode.
  146  */
  147 void
  148 cpu_fork(td1, p2, td2, flags)
  149         register struct thread *td1;
  150         register struct proc *p2;
  151         struct thread *td2;
  152         int flags;
  153 {
  154         register struct proc *p1;
  155         struct pcb *pcb2;
  156         struct mdproc *mdp2;
  157 
  158         p1 = td1->td_proc;
  159         if ((flags & RFPROC) == 0) {
  160                 if ((flags & RFMEM) == 0) {
  161                         /* unshare user LDT */
  162                         struct mdproc *mdp1 = &p1->p_md;
  163                         struct proc_ldt *pldt, *pldt1;
  164 
  165                         mtx_lock_spin(&dt_lock);
  166                         if ((pldt1 = mdp1->md_ldt) != NULL &&
  167                             pldt1->ldt_refcnt > 1) {
  168                                 pldt = user_ldt_alloc(mdp1, pldt1->ldt_len);
  169                                 if (pldt == NULL)
  170                                         panic("could not copy LDT");
  171                                 mdp1->md_ldt = pldt;
  172                                 set_user_ldt(mdp1);
  173                                 user_ldt_deref(pldt1);
  174                         } else
  175                                 mtx_unlock_spin(&dt_lock);
  176                 }
  177                 return;
  178         }
  179 
  180         /* Ensure that td1's pcb is up to date. */
  181         if (td1 == curthread)
  182                 td1->td_pcb->pcb_gs = rgs();
  183 #ifdef DEV_NPX
  184         critical_enter();
  185         if (PCPU_GET(fpcurthread) == td1)
  186                 npxsave(td1->td_pcb->pcb_save);
  187         critical_exit();
  188 #endif
  189 
  190         /* Point the pcb to the top of the stack */
  191         pcb2 = (struct pcb *)(td2->td_kstack +
  192             td2->td_kstack_pages * PAGE_SIZE) - 1;
  193         td2->td_pcb = pcb2;
  194 
  195         /* Copy td1's pcb */
  196         bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
  197 
  198         /* Properly initialize pcb_save */
  199         pcb2->pcb_save = &pcb2->pcb_user_save;
  200 
  201         /* Point mdproc and then copy over td1's contents */
  202         mdp2 = &p2->p_md;
  203         bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
  204 
  205         /*
  206          * Create a new fresh stack for the new process.
  207          * Copy the trap frame for the return to user mode as if from a
  208          * syscall.  This copies most of the user mode register values.
  209          * The -16 is so we can expand the trapframe if we go to vm86.
  210          */
  211         td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1;
  212         bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
  213 
  214         td2->td_frame->tf_eax = 0;              /* Child returns zero */
  215         td2->td_frame->tf_eflags &= ~PSL_C;     /* success */
  216         td2->td_frame->tf_edx = 1;
  217 
  218         /*
  219          * If the parent process has the trap bit set (i.e. a debugger had
  220          * single stepped the process to the system call), we need to clear
  221          * the trap flag from the new frame unless the debugger had set PF_FORK
  222          * on the parent.  Otherwise, the child will receive a (likely
  223          * unexpected) SIGTRAP when it executes the first instruction after
  224          * returning  to userland.
  225          */
  226         if ((p1->p_pfsflags & PF_FORK) == 0)
  227                 td2->td_frame->tf_eflags &= ~PSL_T;
  228 
  229         /*
  230          * Set registers for trampoline to user mode.  Leave space for the
  231          * return address on stack.  These are the kernel mode register values.
  232          */
  233 #ifdef PAE
  234         pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt);
  235 #else
  236         pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir);
  237 #endif
  238         pcb2->pcb_edi = 0;
  239         pcb2->pcb_esi = (int)fork_return;       /* fork_trampoline argument */
  240         pcb2->pcb_ebp = 0;
  241         pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *);
  242         pcb2->pcb_ebx = (int)td2;               /* fork_trampoline argument */
  243         pcb2->pcb_eip = (int)fork_trampoline;
  244         pcb2->pcb_psl = PSL_KERNEL;             /* ints disabled */
  245         /*-
  246          * pcb2->pcb_dr*:       cloned above.
  247          * pcb2->pcb_savefpu:   cloned above.
  248          * pcb2->pcb_flags:     cloned above.
  249          * pcb2->pcb_onfault:   cloned above (always NULL here?).
  250          * pcb2->pcb_gs:        cloned above.
  251          * pcb2->pcb_ext:       cleared below.
  252          */
  253 
  254         /*
  255          * XXX don't copy the i/o pages.  this should probably be fixed.
  256          */
  257         pcb2->pcb_ext = 0;
  258 
  259         /* Copy the LDT, if necessary. */
  260         mtx_lock_spin(&dt_lock);
  261         if (mdp2->md_ldt != NULL) {
  262                 if (flags & RFMEM) {
  263                         mdp2->md_ldt->ldt_refcnt++;
  264                 } else {
  265                         mdp2->md_ldt = user_ldt_alloc(mdp2,
  266                             mdp2->md_ldt->ldt_len);
  267                         if (mdp2->md_ldt == NULL)
  268                                 panic("could not copy LDT");
  269                 }
  270         }
  271         mtx_unlock_spin(&dt_lock);
  272 
  273         /* Setup to release spin count in fork_exit(). */
  274         td2->td_md.md_spinlock_count = 1;
  275         /*
  276          * XXX XEN need to check on PSL_USER is handled
  277          */
  278         td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
  279         /*
  280          * Now, cpu_switch() can schedule the new process.
  281          * pcb_esp is loaded pointing to the cpu_switch() stack frame
  282          * containing the return address when exiting cpu_switch.
  283          * This will normally be to fork_trampoline(), which will have
  284          * %ebx loaded with the new proc's pointer.  fork_trampoline()
  285          * will set up a stack to call fork_return(p, frame); to complete
  286          * the return to user-mode.
  287          */
  288 }
  289 
  290 /*
  291  * Intercept the return address from a freshly forked process that has NOT
  292  * been scheduled yet.
  293  *
  294  * This is needed to make kernel threads stay in kernel mode.
  295  */
  296 void
  297 cpu_set_fork_handler(td, func, arg)
  298         struct thread *td;
  299         void (*func)(void *);
  300         void *arg;
  301 {
  302         /*
  303          * Note that the trap frame follows the args, so the function
  304          * is really called like this:  func(arg, frame);
  305          */
  306         td->td_pcb->pcb_esi = (int) func;       /* function */
  307         td->td_pcb->pcb_ebx = (int) arg;        /* first arg */
  308 }
  309 
  310 void
  311 cpu_exit(struct thread *td)
  312 {
  313 
  314         /*
  315          * If this process has a custom LDT, release it.  Reset pc->pcb_gs
  316          * and %gs before we free it in case they refer to an LDT entry.
  317          */
  318         mtx_lock_spin(&dt_lock);
  319         if (td->td_proc->p_md.md_ldt) {
  320                 td->td_pcb->pcb_gs = _udatasel;
  321                 load_gs(_udatasel);
  322                 user_ldt_free(td);
  323         } else
  324                 mtx_unlock_spin(&dt_lock);
  325 }
  326 
  327 void
  328 cpu_thread_exit(struct thread *td)
  329 {
  330 
  331 #ifdef DEV_NPX
  332         critical_enter();
  333         if (td == PCPU_GET(fpcurthread))
  334                 npxdrop();
  335         critical_exit();
  336 #endif
  337 
  338         /* Disable any hardware breakpoints. */
  339         if (td->td_pcb->pcb_flags & PCB_DBREGS) {
  340                 reset_dbregs();
  341                 td->td_pcb->pcb_flags &= ~PCB_DBREGS;
  342         }
  343 }
  344 
  345 void
  346 cpu_thread_clean(struct thread *td)
  347 {
  348         struct pcb *pcb;
  349 
  350         pcb = td->td_pcb; 
  351         if (pcb->pcb_ext != NULL) {
  352                 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */
  353                 /*
  354                  * XXX do we need to move the TSS off the allocated pages
  355                  * before freeing them?  (not done here)
  356                  */
  357                 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext,
  358                     ctob(IOPAGES + 1));
  359                 pcb->pcb_ext = NULL;
  360         }
  361 }
  362 
  363 void
  364 cpu_thread_swapin(struct thread *td)
  365 {
  366 }
  367 
  368 void
  369 cpu_thread_swapout(struct thread *td)
  370 {
  371 }
  372 
  373 void
  374 cpu_thread_alloc(struct thread *td)
  375 {
  376 
  377         td->td_pcb = (struct pcb *)(td->td_kstack +
  378             td->td_kstack_pages * PAGE_SIZE) - 1;
  379         td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1;
  380         td->td_pcb->pcb_ext = NULL; 
  381         td->td_pcb->pcb_save = &td->td_pcb->pcb_user_save;
  382 }
  383 
  384 void
  385 cpu_thread_free(struct thread *td)
  386 {
  387 
  388         cpu_thread_clean(td);
  389 }
  390 
  391 void
  392 cpu_set_syscall_retval(struct thread *td, int error)
  393 {
  394 
  395         switch (error) {
  396         case 0:
  397                 td->td_frame->tf_eax = td->td_retval[0];
  398                 td->td_frame->tf_edx = td->td_retval[1];
  399                 td->td_frame->tf_eflags &= ~PSL_C;
  400                 break;
  401 
  402         case ERESTART:
  403                 /*
  404                  * Reconstruct pc, assuming lcall $X,y is 7 bytes, int
  405                  * 0x80 is 2 bytes. We saved this in tf_err.
  406                  */
  407                 td->td_frame->tf_eip -= td->td_frame->tf_err;
  408                 break;
  409 
  410         case EJUSTRETURN:
  411                 break;
  412 
  413         default:
  414                 if (td->td_proc->p_sysent->sv_errsize) {
  415                         if (error >= td->td_proc->p_sysent->sv_errsize)
  416                                 error = -1;     /* XXX */
  417                         else
  418                                 error = td->td_proc->p_sysent->sv_errtbl[error];
  419                 }
  420                 td->td_frame->tf_eax = error;
  421                 td->td_frame->tf_eflags |= PSL_C;
  422                 break;
  423         }
  424 }
  425 
  426 /*
  427  * Initialize machine state (pcb and trap frame) for a new thread about to
  428  * upcall. Put enough state in the new thread's PCB to get it to go back 
  429  * userret(), where we can intercept it again to set the return (upcall)
  430  * Address and stack, along with those from upcals that are from other sources
  431  * such as those generated in thread_userret() itself.
  432  */
  433 void
  434 cpu_set_upcall(struct thread *td, struct thread *td0)
  435 {
  436         struct pcb *pcb2;
  437 
  438         /* Point the pcb to the top of the stack. */
  439         pcb2 = td->td_pcb;
  440 
  441         /*
  442          * Copy the upcall pcb.  This loads kernel regs.
  443          * Those not loaded individually below get their default
  444          * values here.
  445          */
  446         bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
  447         pcb2->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE |
  448             PCB_KERNNPX);
  449         pcb2->pcb_save = &pcb2->pcb_user_save;
  450 
  451         /*
  452          * Create a new fresh stack for the new thread.
  453          */
  454         bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
  455 
  456         /* If the current thread has the trap bit set (i.e. a debugger had
  457          * single stepped the process to the system call), we need to clear
  458          * the trap flag from the new frame. Otherwise, the new thread will
  459          * receive a (likely unexpected) SIGTRAP when it executes the first
  460          * instruction after returning to userland.
  461          */
  462         td->td_frame->tf_eflags &= ~PSL_T;
  463 
  464         /*
  465          * Set registers for trampoline to user mode.  Leave space for the
  466          * return address on stack.  These are the kernel mode register values.
  467          */
  468         pcb2->pcb_edi = 0;
  469         pcb2->pcb_esi = (int)fork_return;                   /* trampoline arg */
  470         pcb2->pcb_ebp = 0;
  471         pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */
  472         pcb2->pcb_ebx = (int)td;                            /* trampoline arg */
  473         pcb2->pcb_eip = (int)fork_trampoline;
  474         pcb2->pcb_psl &= ~(PSL_I);      /* interrupts must be disabled */
  475         pcb2->pcb_gs = rgs();
  476         /*
  477          * If we didn't copy the pcb, we'd need to do the following registers:
  478          * pcb2->pcb_cr3:       cloned above.
  479          * pcb2->pcb_dr*:       cloned above.
  480          * pcb2->pcb_savefpu:   cloned above.
  481          * pcb2->pcb_flags:     cloned above.
  482          * pcb2->pcb_onfault:   cloned above (always NULL here?).
  483          * pcb2->pcb_gs:        cloned above.
  484          * pcb2->pcb_ext:       cleared below.
  485          */
  486         pcb2->pcb_ext = NULL;
  487 
  488         /* Setup to release spin count in fork_exit(). */
  489         td->td_md.md_spinlock_count = 1;
  490         td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
  491 }
  492 
  493 /*
  494  * Set that machine state for performing an upcall that has to
  495  * be done in thread_userret() so that those upcalls generated
  496  * in thread_userret() itself can be done as well.
  497  */
  498 void
  499 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
  500         stack_t *stack)
  501 {
  502 
  503         /* 
  504          * Do any extra cleaning that needs to be done.
  505          * The thread may have optional components
  506          * that are not present in a fresh thread.
  507          * This may be a recycled thread so make it look
  508          * as though it's newly allocated.
  509          */
  510         cpu_thread_clean(td);
  511 
  512         /*
  513          * Set the trap frame to point at the beginning of the uts
  514          * function.
  515          */
  516         td->td_frame->tf_ebp = 0; 
  517         td->td_frame->tf_esp =
  518             (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
  519         td->td_frame->tf_eip = (int)entry;
  520 
  521         /*
  522          * Pass the address of the mailbox for this kse to the uts
  523          * function as a parameter on the stack.
  524          */
  525         suword((void *)(td->td_frame->tf_esp + sizeof(void *)),
  526             (int)arg);
  527 }
  528 
  529 int
  530 cpu_set_user_tls(struct thread *td, void *tls_base)
  531 {
  532         struct segment_descriptor sd;
  533         uint32_t base;
  534 
  535         /*
  536          * Construct a descriptor and store it in the pcb for
  537          * the next context switch.  Also store it in the gdt
  538          * so that the load of tf_fs into %fs will activate it
  539          * at return to userland.
  540          */
  541         base = (uint32_t)tls_base;
  542         sd.sd_lobase = base & 0xffffff;
  543         sd.sd_hibase = (base >> 24) & 0xff;
  544         sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */
  545         sd.sd_hilimit = 0xf;
  546         sd.sd_type  = SDT_MEMRWA;
  547         sd.sd_dpl   = SEL_UPL;
  548         sd.sd_p     = 1;
  549         sd.sd_xx    = 0;
  550         sd.sd_def32 = 1;
  551         sd.sd_gran  = 1;
  552         critical_enter();
  553         /* set %gs */
  554         td->td_pcb->pcb_gsd = sd;
  555         if (td == curthread) {
  556                 PCPU_GET(fsgs_gdt)[1] = sd;
  557                 load_gs(GSEL(GUGS_SEL, SEL_UPL));
  558         }
  559         critical_exit();
  560         return (0);
  561 }
  562 
  563 /*
  564  * Convert kernel VA to physical address
  565  */
  566 vm_paddr_t
  567 kvtop(void *addr)
  568 {
  569         vm_paddr_t pa;
  570 
  571         pa = pmap_kextract((vm_offset_t)addr);
  572         if (pa == 0)
  573                 panic("kvtop: zero page frame");
  574         return (pa);
  575 }
  576 
  577 #ifdef SMP
  578 static void
  579 cpu_reset_proxy()
  580 {
  581         cpuset_t tcrp;
  582 
  583         cpu_reset_proxy_active = 1;
  584         while (cpu_reset_proxy_active == 1)
  585                 ;       /* Wait for other cpu to see that we've started */
  586         CPU_SETOF(cpu_reset_proxyid, &tcrp);
  587         stop_cpus(tcrp);
  588         printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
  589         DELAY(1000000);
  590         cpu_reset_real();
  591 }
  592 #endif
  593 
  594 void
  595 cpu_reset()
  596 {
  597 #ifdef XBOX
  598         if (arch_i386_is_xbox) {
  599                 /* Kick the PIC16L, it can reboot the box */
  600                 pic16l_reboot();
  601                 for (;;);
  602         }
  603 #endif
  604 
  605 #ifdef SMP
  606         cpuset_t map;
  607         u_int cnt;
  608 
  609         if (smp_active) {
  610                 map = all_cpus;
  611                 CPU_CLR(PCPU_GET(cpuid), &map);
  612                 CPU_NAND(&map, &stopped_cpus);
  613                 if (!CPU_EMPTY(&map)) {
  614                         printf("cpu_reset: Stopping other CPUs\n");
  615                         stop_cpus(map);
  616                 }
  617 
  618                 if (PCPU_GET(cpuid) != 0) {
  619                         cpu_reset_proxyid = PCPU_GET(cpuid);
  620                         cpustop_restartfunc = cpu_reset_proxy;
  621                         cpu_reset_proxy_active = 0;
  622                         printf("cpu_reset: Restarting BSP\n");
  623 
  624                         /* Restart CPU #0. */
  625                         /* XXX: restart_cpus(1 << 0); */
  626                         CPU_SETOF(0, &started_cpus);
  627                         wmb();
  628 
  629                         cnt = 0;
  630                         while (cpu_reset_proxy_active == 0 && cnt < 10000000)
  631                                 cnt++;  /* Wait for BSP to announce restart */
  632                         if (cpu_reset_proxy_active == 0)
  633                                 printf("cpu_reset: Failed to restart BSP\n");
  634                         enable_intr();
  635                         cpu_reset_proxy_active = 2;
  636 
  637                         while (1);
  638                         /* NOTREACHED */
  639                 }
  640 
  641                 DELAY(1000000);
  642         }
  643 #endif
  644         cpu_reset_real();
  645         /* NOTREACHED */
  646 }
  647 
  648 static void
  649 cpu_reset_real()
  650 {
  651         struct region_descriptor null_idt;
  652 #ifndef PC98
  653         int b;
  654 #endif
  655 
  656         disable_intr();
  657 #ifdef XEN
  658         if (smp_processor_id() == 0)
  659                 HYPERVISOR_shutdown(SHUTDOWN_reboot);
  660         else
  661                 HYPERVISOR_shutdown(SHUTDOWN_poweroff);
  662 #endif 
  663 #ifdef CPU_ELAN
  664         if (elan_mmcr != NULL)
  665                 elan_mmcr->RESCFG = 1;
  666 #endif
  667 
  668         if (cpu == CPU_GEODE1100) {
  669                 /* Attempt Geode's own reset */
  670                 outl(0xcf8, 0x80009044ul);
  671                 outl(0xcfc, 0xf);
  672         }
  673 
  674 #ifdef PC98
  675         /*
  676          * Attempt to do a CPU reset via CPU reset port.
  677          */
  678         if ((inb(0x35) & 0xa0) != 0xa0) {
  679                 outb(0x37, 0x0f);               /* SHUT0 = 0. */
  680                 outb(0x37, 0x0b);               /* SHUT1 = 0. */
  681         }
  682         outb(0xf0, 0x00);               /* Reset. */
  683 #else
  684 #if !defined(BROKEN_KEYBOARD_RESET)
  685         /*
  686          * Attempt to do a CPU reset via the keyboard controller,
  687          * do not turn off GateA20, as any machine that fails
  688          * to do the reset here would then end up in no man's land.
  689          */
  690         outb(IO_KBD + 4, 0xFE);
  691         DELAY(500000);  /* wait 0.5 sec to see if that did it */
  692 #endif
  693 
  694         /*
  695          * Attempt to force a reset via the Reset Control register at
  696          * I/O port 0xcf9.  Bit 2 forces a system reset when it
  697          * transitions from 0 to 1.  Bit 1 selects the type of reset
  698          * to attempt: 0 selects a "soft" reset, and 1 selects a
  699          * "hard" reset.  We try a "hard" reset.  The first write sets
  700          * bit 1 to select a "hard" reset and clears bit 2.  The
  701          * second write forces a 0 -> 1 transition in bit 2 to trigger
  702          * a reset.
  703          */
  704         outb(0xcf9, 0x2);
  705         outb(0xcf9, 0x6);
  706         DELAY(500000);  /* wait 0.5 sec to see if that did it */
  707 
  708         /*
  709          * Attempt to force a reset via the Fast A20 and Init register
  710          * at I/O port 0x92.  Bit 1 serves as an alternate A20 gate.
  711          * Bit 0 asserts INIT# when set to 1.  We are careful to only
  712          * preserve bit 1 while setting bit 0.  We also must clear bit
  713          * 0 before setting it if it isn't already clear.
  714          */
  715         b = inb(0x92);
  716         if (b != 0xff) {
  717                 if ((b & 0x1) != 0)
  718                         outb(0x92, b & 0xfe);
  719                 outb(0x92, b | 0x1);
  720                 DELAY(500000);  /* wait 0.5 sec to see if that did it */
  721         }
  722 #endif /* PC98 */
  723 
  724         printf("No known reset method worked, attempting CPU shutdown\n");
  725         DELAY(1000000); /* wait 1 sec for printf to complete */
  726 
  727         /* Wipe the IDT. */
  728         null_idt.rd_limit = 0;
  729         null_idt.rd_base = 0;
  730         lidt(&null_idt);
  731 
  732         /* "good night, sweet prince .... <THUNK!>" */
  733         breakpoint();
  734 
  735         /* NOTREACHED */
  736         while(1);
  737 }
  738 
  739 /*
  740  * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
  741  */
  742 static void
  743 sf_buf_init(void *arg)
  744 {
  745         struct sf_buf *sf_bufs;
  746         vm_offset_t sf_base;
  747         int i;
  748 
  749         nsfbufs = NSFBUFS;
  750         TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs);
  751 
  752         sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask);
  753         TAILQ_INIT(&sf_buf_freelist);
  754         sf_base = kmem_alloc_nofault(kernel_map, nsfbufs * PAGE_SIZE);
  755         sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP,
  756             M_NOWAIT | M_ZERO);
  757         for (i = 0; i < nsfbufs; i++) {
  758                 sf_bufs[i].kva = sf_base + i * PAGE_SIZE;
  759                 TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry);
  760         }
  761         sf_buf_alloc_want = 0;
  762         mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF);
  763 }
  764 
  765 /*
  766  * Invalidate the cache lines that may belong to the page, if
  767  * (possibly old) mapping of the page by sf buffer exists.  Returns
  768  * TRUE when mapping was found and cache invalidated.
  769  */
  770 boolean_t
  771 sf_buf_invalidate_cache(vm_page_t m)
  772 {
  773         struct sf_head *hash_list;
  774         struct sf_buf *sf;
  775         boolean_t ret;
  776 
  777         hash_list = &sf_buf_active[SF_BUF_HASH(m)];
  778         ret = FALSE;
  779         mtx_lock(&sf_buf_lock);
  780         LIST_FOREACH(sf, hash_list, list_entry) {
  781                 if (sf->m == m) {
  782                         /*
  783                          * Use pmap_qenter to update the pte for
  784                          * existing mapping, in particular, the PAT
  785                          * settings are recalculated.
  786                          */
  787                         pmap_qenter(sf->kva, &m, 1);
  788                         pmap_invalidate_cache_range(sf->kva, sf->kva +
  789                             PAGE_SIZE);
  790                         ret = TRUE;
  791                         break;
  792                 }
  793         }
  794         mtx_unlock(&sf_buf_lock);
  795         return (ret);
  796 }
  797 
  798 /*
  799  * Get an sf_buf from the freelist.  May block if none are available.
  800  */
  801 struct sf_buf *
  802 sf_buf_alloc(struct vm_page *m, int flags)
  803 {
  804         pt_entry_t opte, *ptep;
  805         struct sf_head *hash_list;
  806         struct sf_buf *sf;
  807 #ifdef SMP
  808         cpuset_t other_cpus;
  809         u_int cpuid;
  810 #endif
  811         int error;
  812 
  813         KASSERT(curthread->td_pinned > 0 || (flags & SFB_CPUPRIVATE) == 0,
  814             ("sf_buf_alloc(SFB_CPUPRIVATE): curthread not pinned"));
  815         hash_list = &sf_buf_active[SF_BUF_HASH(m)];
  816         mtx_lock(&sf_buf_lock);
  817         LIST_FOREACH(sf, hash_list, list_entry) {
  818                 if (sf->m == m) {
  819                         sf->ref_count++;
  820                         if (sf->ref_count == 1) {
  821                                 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
  822                                 nsfbufsused++;
  823                                 nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
  824                         }
  825 #ifdef SMP
  826                         goto shootdown; 
  827 #else
  828                         goto done;
  829 #endif
  830                 }
  831         }
  832         while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) {
  833                 if (flags & SFB_NOWAIT)
  834                         goto done;
  835                 sf_buf_alloc_want++;
  836                 mbstat.sf_allocwait++;
  837                 error = msleep(&sf_buf_freelist, &sf_buf_lock,
  838                     (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0);
  839                 sf_buf_alloc_want--;
  840 
  841                 /*
  842                  * If we got a signal, don't risk going back to sleep. 
  843                  */
  844                 if (error)
  845                         goto done;
  846         }
  847         TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
  848         if (sf->m != NULL)
  849                 LIST_REMOVE(sf, list_entry);
  850         LIST_INSERT_HEAD(hash_list, sf, list_entry);
  851         sf->ref_count = 1;
  852         sf->m = m;
  853         nsfbufsused++;
  854         nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
  855 
  856         /*
  857          * Update the sf_buf's virtual-to-physical mapping, flushing the
  858          * virtual address from the TLB.  Since the reference count for 
  859          * the sf_buf's old mapping was zero, that mapping is not 
  860          * currently in use.  Consequently, there is no need to exchange 
  861          * the old and new PTEs atomically, even under PAE.
  862          */
  863         ptep = vtopte(sf->kva);
  864         opte = *ptep;
  865 #ifdef XEN
  866        PT_SET_MA(sf->kva, xpmap_ptom(VM_PAGE_TO_PHYS(m)) | pgeflag
  867            | PG_RW | PG_V | pmap_cache_bits(m->md.pat_mode, 0));
  868 #else
  869         *ptep = VM_PAGE_TO_PHYS(m) | pgeflag | PG_RW | PG_V |
  870             pmap_cache_bits(m->md.pat_mode, 0);
  871 #endif
  872 
  873         /*
  874          * Avoid unnecessary TLB invalidations: If the sf_buf's old
  875          * virtual-to-physical mapping was not used, then any processor
  876          * that has invalidated the sf_buf's virtual address from its TLB
  877          * since the last used mapping need not invalidate again.
  878          */
  879 #ifdef SMP
  880         if ((opte & (PG_V | PG_A)) ==  (PG_V | PG_A))
  881                 CPU_ZERO(&sf->cpumask);
  882 shootdown:
  883         sched_pin();
  884         cpuid = PCPU_GET(cpuid);
  885         if (!CPU_ISSET(cpuid, &sf->cpumask)) {
  886                 CPU_SET(cpuid, &sf->cpumask);
  887                 invlpg(sf->kva);
  888         }
  889         if ((flags & SFB_CPUPRIVATE) == 0) {
  890                 other_cpus = all_cpus;
  891                 CPU_CLR(cpuid, &other_cpus);
  892                 CPU_NAND(&other_cpus, &sf->cpumask);
  893                 if (!CPU_EMPTY(&other_cpus)) {
  894                         CPU_OR(&sf->cpumask, &other_cpus);
  895                         smp_masked_invlpg(other_cpus, sf->kva);
  896                 }
  897         }
  898         sched_unpin();
  899 #else
  900         if ((opte & (PG_V | PG_A)) ==  (PG_V | PG_A))
  901                 pmap_invalidate_page(kernel_pmap, sf->kva);
  902 #endif
  903 done:
  904         mtx_unlock(&sf_buf_lock);
  905         return (sf);
  906 }
  907 
  908 /*
  909  * Remove a reference from the given sf_buf, adding it to the free
  910  * list when its reference count reaches zero.  A freed sf_buf still,
  911  * however, retains its virtual-to-physical mapping until it is
  912  * recycled or reactivated by sf_buf_alloc(9).
  913  */
  914 void
  915 sf_buf_free(struct sf_buf *sf)
  916 {
  917 
  918         mtx_lock(&sf_buf_lock);
  919         sf->ref_count--;
  920         if (sf->ref_count == 0) {
  921                 TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry);
  922                 nsfbufsused--;
  923 #ifdef XEN
  924 /*
  925  * Xen doesn't like having dangling R/W mappings
  926  */
  927                 pmap_qremove(sf->kva, 1);
  928                 sf->m = NULL;
  929                 LIST_REMOVE(sf, list_entry);
  930 #endif
  931                 if (sf_buf_alloc_want > 0)
  932                         wakeup(&sf_buf_freelist);
  933         }
  934         mtx_unlock(&sf_buf_lock);
  935 }
  936 
  937 /*
  938  * Software interrupt handler for queued VM system processing.
  939  */   
  940 void  
  941 swi_vm(void *dummy) 
  942 {     
  943         if (busdma_swi_pending != 0)
  944                 busdma_swi();
  945 }
  946 
  947 /*
  948  * Tell whether this address is in some physical memory region.
  949  * Currently used by the kernel coredump code in order to avoid
  950  * dumping the ``ISA memory hole'' which could cause indefinite hangs,
  951  * or other unpredictable behaviour.
  952  */
  953 
  954 int
  955 is_physical_memory(vm_paddr_t addr)
  956 {
  957 
  958 #ifdef DEV_ISA
  959         /* The ISA ``memory hole''. */
  960         if (addr >= 0xa0000 && addr < 0x100000)
  961                 return 0;
  962 #endif
  963 
  964         /*
  965          * stuff other tests for known memory-mapped devices (PCI?)
  966          * here
  967          */
  968 
  969         return 1;
  970 }

Cache object: 7c92f594a5dc560c9ab80b987cc865fe


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.